The switching frequency of an LED driver refers to the rate at which the driver switches ON and OFF to regulate the current supplied to the LEDs. It is a crucial parameter in the operation of LED drivers and affects the performance, efficiency, and other characteristics of the LED lighting system.

The switching frequency determines the speed at which the driver turns ON and OFF to adjust the current. It is measured in Hertz (Hz) and can vary widely depending on the specific driver design. A modern LED driver intended for portable applications should be able to switch at frequencies of up to 1 MHz.

The switching frequency can have a significant impact on the efficiency of the LED driver and the overall lighting system. Higher switching frequencies can lead to higher switching losses, which may reduce the driver's efficiency. Conversely, lower switching frequencies often require larger inductors and capacitors to store and transfer energy effectively, i.e., slower switching speed allows more time for energy to accumulate in the inductor during the on-state and discharge during the off-state.

The switching frequency can also affect the ability of the LED driver to support dimming and reduce flicker. Some LED drivers have adjustable switching frequencies to optimize dimming performance and minimize perceptible flicker when LEDs are dimmed.